Wrong comment in Standard Governor's execute function

Description

The following comment is present in StandardGovernor's execute function: // Proposals have voteStart=N and voteEnd=N, and can be executed only during epochs N+1 and N+2. This, however, is not the current behaviour of the contract.

As confirmed by the client, approved proposals can only be executed 1 epoch after voteEnd and not 2 epochs as the comment suggests.

Recommendation

Update the comment so it explains the actual behaviour of epoch execution: // Proposals have voteStart=N and voteEnd=N, and can be executed only during N+1 epoch.

Status

Addressed in #22bd53c.